1980 Mariner M-90 hp overheat sensor, I think

racerone

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Find the yellow wires.-----Do an ohm test on the 2 yellow wires.-----Ohm test one yellow wire to ground.----If good then replace the rectifier.
 

The Force power

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In addition......
Check the voltage at the DC Pos. terminal of the Rectifier to see if its the same as at the battery.
If higher at the rectifier (13 to 16VDC) you have "bad wiring" to the battery
 

merc850

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What oil mix did you use, should be 50:1 (16oz to 6 gal of gas) and well mixed - add the oil while filling tank. And don't rev the hell out of it in neutral keep it below 2500rpms.
 

racerone

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You could have a float valve issue or a fuel pump internal leak.------Then it will use a lot of fuel.----" didn't take long to run a gallon through it " means very little.
 

Rick Stevens

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Thanks folks!!!! I will do those checks and I used 50-1 and I blew compressed up into the tell tale hole and fired it up tonight and the pee hole squirts nicely now and I got a bunch of gooy butterscotch looking crap come out the prop when final run today. Must have been somewhere when I blew the lines out.......
 

Rick Stevens

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OK I did the ohm test on the rectifier. The only thing that read right was the dc volts, 12.68 same as battery but nothing else ohmed out. I need to mention when I got the engine the 2 yellow wires were almost fraided all the way through bare wires for about an inch, only a couple strands left I fixed them with heat shrink . I used this sites trouble shooting with yours and I am assuming the bare wires fried the rectifier...


http://myoutboardengine.com/rectifier.html
 

Rick Stevens

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And the newst thing came up after I blew out the lines. That light brown gooey stuff coming out of the prop when running didnt do it before I blew the lines out. and before when running the prop would turn in reverse real slow while running now it will move a little then slow down then move again. I am wondering if the rear seal in the LU went out and gear lube is blowing out the exhasut.
 

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Rick Stevens

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I changed the LU oil. MAN what a smell, Very nasty, stunk up the whole shop. Refilled from the bottom till run out the vent on top. Maybe it was just time for the seal to go, seeing how it sat for 6 years or so without running.
 

racerone

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That gooey stuff is normal.-------That question is asked 3 times a week here.------The answer is NORMAL.
 

The Force power

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OK I did the ohm test on the rectifier. The only thing that read right was the dc volts, 12.68 same as battery but nothing else ohmed out. I need to mention when I got the engine the 2 yellow wires were almost fraided all the way through bare wires for about an inch, only a couple strands left I fixed them with heat shrink . I used this sites trouble shooting with yours and I am assuming the bare wires fried the rectifier...

possible that the rectifier is no good but... the yellow wires of the Stator supplying AC voltage to the rectifier could be the cause

cut back yellow wires as far back as needed and solder on new, check if good other wise replace Rectifier also
 

Rick Stevens

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possible that the rectifier is no good but... the yellow wires of the Stator supplying AC voltage to the rectifier could be the cause

cut back yellow wires as far back as needed and solder on new, check if good other wise replace Rectifier also

Yeah I fixed the wires and just ordered the rectifier. Thanks ,,Its kinda hard starting also. Hoping the new rectifier will help with that.
 

The Force power

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WOW so I shouldn't have used the seafoam? I thought that was standard use of de carbing. I hope I didn't screw up something. Thanks

Seafoam does not remove carbon as much as everybody likes to believe & no it does not "screw up" things; just a nice smoke show
 

The Force power

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Yeah I fixed the wires and just ordered the rectifier. Thanks ,,Its kinda hard starting also. Hoping the new rectifier will help with that.

"hard starting" has nothing to do with the charging-system, however you should pay close attention to the remaining wires on the stater that produce the power to energize the ignition-coils
bad wiring can/will cause NO/INTERMITTENT/POOR sparking conditions
 
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Rick Stevens

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"hard starting" has nothing to do with the charging-system, however you should pay close attention to the remaining wires on the stater that produce the power to energize the ignition-coils
bad wiring can/will cause NO/INTERMITTENT/POOR sparking conditions

Thanks guys. There are 100 videos on utube showing and stating seafoam de crabs LOL but, thanks for that, and I will check the stator wires, The hard starting just kinda hits a couple cylinders then after a lil cranking they all finally hit then runs like a champ.
 

Rick Stevens

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Well I got the new rectifier nada. It will start but hard and after I give a shot of starter fluid it hit s and hits harder than starts. I can shut it off and start it 5 minutes later and it fires up right away. The compression on this 6 is from 1-6 156-170-161-160-160-161. Carbs seem ok I give it a little gas, not much and it revs right up. I will start on testing the Stator I guess. Funny thing is nothing is testing out like It should.. I know how to use an Ohm reader
 

Rick Stevens

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OK I tested the stator to this members suggestions and it works.

Chris1956 - Chris1956

Chris1956
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#4
October 8th, 2017, 06:35 AM
It is always prudent to disconnect the stator before testing, to isolate the possible fault to the stator itself.

Battery CDI ignition motors have 2 wire stators. Two wire stators only charge the battery, via rectified AC current. With the motor running, some AC voltage on the yellow wires will indicate they are working.

ADI motors have more than two wire stators. I have the specs for 6 cylinder motors,if you need them.

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The thing almost sounds like its flooding out when first starting and I hear something arching around the coils. I cant see any sparking. More work I guess

That arching isn't all the time, it is hit a miss!
 
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